<template>
  <div>
    <!-- 
      递归查找：代码繁琐、性能低效
      callback ref
        1.主动通知 (setXxxRef)
        2.主动获取 (getXxxRef)
     -->
    <children-a />
  </div>
</template>

<script>
import ChildrenA from "./ChildrenA.vue";
export default {
  components: { ChildrenA },
};
</script>
